When you are in Guwahati ,below are must thing to do:-
1 Try authentic Assamese meal.Restaurant option :- Khorika , Gam Delicacy. Additional:Tera Mayya is good for nightlife its in buzz.Don't miss breakfast in mocha.
2.If you love street shopping must vist fancy bazar.
Additional:If want to buy something authentic-Assamese japi(decorative piece made of bamboo).Buy silk &Muga cloth(bit expensive).
3.Do Experience lunch in floating resturant in boat by riverside.
4.Kamkhya ,Umanda temple are must visit.
5.Few hours away is Kaziranga national park.Just book a cab and spend a night there and enjoy morning safari .